Train-signal system



March 20, 1928.

E. c. STAFFORD TRAIN SIGNAL SYSTEM 2 Sheets-Sheet 1 Filed March 7. 1921 March 20, 1928. 1,662,988

E. c. STAFFORD TRAIN SIGNAL SYSTEM Filed March '7. 1921 2 Sheet's-Sheet 2,

der

I z5 Z7 z5 Patented Mar. 20, 1928.

unirse sra'res Param EARL C. STAFFORD,' OF PHILADELPHIA, IENNSYLVANIA, ASSIGNOR TOTHE; UNITED STATES TRAIN SIGNAL COMPANY, OF `PORTLAND, MAINE, kA CORPORATION 0F l MAINE.

, V'rniiiiv-SIGNAL sYsTEi/i. 'Y

Application iledvMaroh 7, 1921. Serial No. 450,195.

My said invention relates to certain improvements over the train signal system shown in application No. .380,286 of Benn and( Davies, iiled May 10,1920, and it is an object: of the same to provide means whereby the system may be used with equal facility in a train composed wholly of' cars equipped with the electro-pneumatic signaling device shown in my prior application No. 380,151, iiled May 10, 1920, or in a train comprising cars soequippediand others not so equipped.

'Referring tothe accompanying drawings which are made a parthereof and on vwhich similar `referencev characters indicate similar parts,

Figure 1 `shows a diagrammatic View of an electriccircuit for a train unit such as apassenger car or-the like together with the cooperating instrumentalities for giving a signal or transmitting the same to another portion-of thevtrain,

Figure 2 is asimilarfview of the signalingl instrumental'ities for a train unit such asl a locomotive, Y n

Figure 3`is a plan of'my air relay, and i Figure 4 a-vertical section thereof.

In the drawings reference character 5 represents a signaling device Vsuch as is shown in my prior application above referred to comprising preferablyy both visual and audible instrumentalities.' A pipe 6 is connected to the air brake train pipe and to an audibleV device on the signaling means 5 such as a. whistle or sisser sc that the compressed airf'from the pipe will operate the signal when the circuit is. broken.

.Reference numerali7 indicates a section of a conventional air signal train pipe. A branch 8 connects the train signal pipe to an air relay or fluid pressure circuit controller 9the details yofwhich are fully eX- plainedl in my co-pending application of evendate herewith Serial No. 450,196. The section of air brake train .pipe to which pipe 6 is connected and the Asection 7 ,of the train signal pipe are coupledtogether by means of pipe couplings suchas are shown in applicationNo. 380,286 abovereferred to, or' in any-other desirable manner.

The circuit comprisesa conductor 10 with a battery llfconnected'between sections of the `same and a conductor 12 comprising sections-co-actingfwith a circuit controller 13,

the signaling device 5 anda secondl circuit Y controller 14. At the'ends of the carare switches 15 and 16 by means of which-the circuit" may be closed at the proper end .of

thel front or the rear unit of the train.' The long'and'shortdevicesshown at' 17 and 18 represent the long and short jaws ofk anair brake hose 'coupling as in co-pending appli--` cation No. 380,286 and it will'be'evident'that train units carrying systemsuch as shown may bexconnected end to endv in series re#I gardlessof which end isJforemost.

The circuit. controller 14 is or maybe yas y.

disclosed in coLpending application No.

380,286 of Benn and Davies, iile'd' May 10,

1920, being manually controlled by the usual conductors cord or a cord running vparallel tothe opposite endsofthefparticular car orother unit so that the controllermay be operated from any'part' of the car or other train unit on which-thesame is located.l

To the system of the prior application Ihave added a circuitcontroller 13`comprisingA a fluid-pressure circuit=controller attached to the air signaltrain pipe containing airunder pressure. This device is shownl in detail in Figures ifand yand'comprises base. members 25 and 26,'orming` therebetween a. cavity in which is a dia- 'phragmw27-` A plate 28 rests on the diaphragm and prevents the Same from being 7o thereto attached'to the rings v`19`and running 3 blown through an aperture in anextension` 29 on base member 26. The base member 25 hasxa threadedfopening to whichl pipe; 8` is connected for applying compressed airz to the diaphragm. The diaphragm is normally held down by a spring 30 inthe extension,

a screw 31having threaded connection with said plate and collars beingpformedof any' suitable insulating material. Theflever 34 carries a movable contact member 40jand`is normally held in the position shown by a spring 11l attached by screws or the like to the lever andthe basemember 26. Contact is adapted to engage stationary contact 41 mounted in a support 42 attached to eXtenf sion 29 by screws 37 in the same manner as support 36.V The contact 41 'forms a part of a screw 43 by means of which it may be adjusted' toward Vand away' from contact` 40. A'nut744on screw 43 constitutes meansfor locking the same in adjusted position. VAV block 45 fastened to base member 26 by P screws or other means .forms a.. support for a pair of binding posts 46 connected to supportsand 42 wby wires 47 'and `screws 48,

. the binding postsfbeing connected to conduetorff12.y The signaling devices use so littleair they do lnot effect any reduction' LJ pressure in the signal trainpipe is reduced the circuitvisbroken at `13 and asignalis operated on each unit4 of the train including not closed through such a car.

bothcars and locomotives, this beingtrue, however, only if all train units are equipped Vwith electro-pneumatic signalling devices, or

otherwiseonlyof those equipped units that vare connected in a. circuit.

@,'Prefe'rablyvv I. so arrange the devices as to be 'very sensitive, so that avery slight change f ofpressure is suilicient to break the circuits an'deause operation of the signalingdevices. Asexplained in my co-pending application IA arrange'the signaling devices so as to requirea minimum oi power in the circuit for operating the same. Y

' I have also modified the equipment ofthe locomotive shown in application No. 380,286

by adding thereto abattery 11, a circuitcontroller 13, with its controlling means at- Atached'to the train signal pipe 7 and a valve 20 of any conventional form in the branch 8 with aconductors cord 21 for operating the same to rlower the pressure in the pipe. In my'present arrangement it is immaterial whether the locomotive is connected to an equipped 'car or an unequipped one so long as there isan air pipe on thecar and antunequipped car may also be connectedl anywherein the train of Vcars without-intertering with the operation of the signaling means on the equipped cars. Signal cords extending from frontto rear of the cab,'0r roinrfront to rear of the engine, if desired, extend forward and back fromm-ings 19- on circuit-controller 14 of the engine.V Y It is evident that operation of the circuit controllers v14 will not serve to transmit a signal past an unequipped car as a'circuit is I now a member of atrain crew on an equipped unit shoulddesire to transmit a signal pastran unequipped unit Yto the engineer and he attempted to operate the controller 14 the signal, of course, will not be transmitted. Se-

curing no response after one or two attempts he will naturally use the other operating means, i. e. a cord connected to the ordinary conductors valve. l f i If the entire train is equipped with the electi'o-pneuinatie signaling device the engineer `will usevthe circuit controller..14 only and so will the entire train cre'w since in such a casethe compressed air signal pipe becomes Y a. mere supei'fluity. As in the priorrapplication the system `will be operated by parting of the train`,"grounding of a wire, or break- ,devices will constitute part of the trainrand I in such case, providedfthey have' an'k air signal pipe, the signaling willV be done-,by the.

train crew by pulling accord-toy operate .the conduetorls valve of ythe'usual Vtype now found in'trains for signaling the vengineer and the engineer may signal back .tothe crew by pullingr the-cord21 to .operate. valve"20.`

Anydecreasejof'air pressure in the pipe will of course break the circuit in every car and 1 on the locomotive and thus give both visible and audible signals on allfcars connected in a. circuit nwith theeng'ine o'r with Veach other. It maybe founddesirable where a train is thus made up of equipped and nnequipped the air relay andto providea switch at. 22 in one branch of thedivided circuit in addi* tion to the switch 13 inthe other. lTheelectro-pneumatic system may then be usedV alone -if all: the train units Aare equipped With 'my electroqane'umatic.signalling devices. The signalpipeA seetionsin .this case need not be coupled up,fas the pipe is not used at all. It may also be desirable, as shown'in Figure 2 -nnits to divide the engine circuit adjacent to connect a switch 14 to the envineers cord l i'or the `engine .valve-.wherebyvboth will be operated whenever either is actuated by the engineer. for 'use .only whereV unequipped cars are liable lto'be used as a portion of atrain.

This expedient-is .contemplated Y It will be obvious that I'may also vomit the circuit controller on the engine andrif this be done the engineer can signal to the. crew by the. cordl operated reduction valve and signal pipe, .andthe crewmay signal to the engineer .bythe conductors valve and signal pipe in similar fashion; if one of the train ycrew should pull the cord attached to controller 14 on a car' he. will, get no response from `the engineer 4and `will thereby perceive ,his error asthe electric circuit is not colm-y pleted throughout the train. It will be understood that the Vusual pressure is kept up application, No. 450,196. The electro-pneu matic signaling instrument and a battery are also placed on the engine and the relay operated with ordinary stra-ight air pressure from the train signal pipe. By thus substr tuting the air relay and signal for the. whistle I enable the engineer to signal back to the train crew as well as the train crew to signal to the engineer in the usual manner, the only difference being that a signal in the cab is operated instead of the engine whistle.

I may also attach the pipe 6 to the signal pipe instead of the brake pipe if desired. In

such case operation of circuit controller 14- would lower the pressure in signal pipe? and this would cause the air relay or relays to operate and open the circuit at each switch 13.

Other modifications of my'system will occur to those skilled in the art of signaling and therefore I do not limit myself to the precise form thereof shown inthe drawings and described in the specification, the true scope of the invention being set forth in the appended claims.

Having thus fully described my said invention, what I claim as new and desire to secure by Letters Patent, is:

l. In a train signaling system, a plurality of signaling devices mounted on different units of thetrain comprising an audible signaling means connected to the train air brake pipe, means on each train unit whereby a closed electric circuit may operate on such unit or between a plurality of units and means connected to the air signal train pipe for breaking said circuit to cause operation of the signaling device, substantially as set forth.

2. In a train signaling system, a plurality of signaling devices mounted on different units of the'train comprising an audible signaling ymeans connecte-d to the train air brake pipe, a normally-closed electric circuit extending through the train and means on' each train unit connected to an air line of the train for breaking said circuit to cause operation of the signaling device, substantially as set forth.

3. In a train signaling system, the combination of a plurality of signaling devices mounted on individual tra-in units, a-n electric circuit adapted to connect a plurality of equipped train units, manually operated circuit controllers for breaking the circuit t0 transmit a signal from one unit to another in either direction of the length of the train,

and means whereby the signaling device on the engine may be operated from other train units itt' an unequipped train unit is interposed between the equipped units of the train, substantially as set forth.

a. A train signaling system comprising la signal on alocomotive, a train pipe connected thereto for operating the signal byvariations of air pressure, meansincluding an electric circuit Vnormally preventing operation of the signal said circuit being divided for'a part of its course, a manually voperated switch in one branch of the circuit,

a fluid-pressurc.-controlled switch in. the other branch, a second train air'pipe connected thereto, a normally closed circuit controller in the main line of the electric circuit,a valve in the second train air pipe andmeans for simultaneously opening said valve and actuating said circuit closerto break the circuit, substantially as set forth.

5. A train signaling system comprising a signal on a locomotive, a train pipe connected thereto for operating the signal by variations of air pressure, means including .an electric circuit normally preventing operation of the signal, said circuit being divided for a part of its course, a manually operated switch in one branch of the circuit, a iluid- Y pressure-controlled switch in the other branch, a second train pipe connected thereto, avalve in thesecond train pipe, and a cord connected vto said valve for opera-ting' it, substantially as set forth. v

6. In a signaling system forl trains, electrically operatedsignals, a train signal pipe, a normally closed electric circuit on the train, means for operating the signals when the circuit is broken, and means including a fluid pressure operated switch connected to the signal pipe adapted to break the circuit on reduction of pressure in said pipe, substantially as set forth.

7 A. train signaling systemcomprising a pneumatic signal on each of a Vsuccession of train units, common vpneumatic means for operating all of'said signals including a train pipe connected to each signal, means including a circuit common to all of said units controlling all of saidsignaling devices and including alternativev branch circuits onl one unit, a switch in each branch, a second train pipe, means including` a- Huid pressure switch connecting the train pipe tov one of each pair of circuits, and a circuit controller in said circuit on each'trainunit operable by a conductors cord, substantially as set forth. 1 y

In witness whereof, I have hereunto set my hand at Vashington, District of Columbia, this 19th day of February, A. D. nineteen hundred and twenty-one. 

